Surgical stapling device for performing circular anastomoses

ABSTRACT

This application is directed to a surgical stapling device for performing circular anastomoses. The surgical stapling device includes a handle portion, an elongated body portion and a head portion including an anvil assembly and a shell assembly. The handle portion includes a rotatable approximation knob for approximating the anvil and shell assemblies and a firing trigger for actuating a firing mechanism for ejecting staples positioned within the shell assembly. The firing trigger forms one link of a two bar linkage provided to actuate the firing mechanism. The anvil assembly includes a tiltable anvil which will tilt automatically after firing of the device and unapproximating the anvil and shell assemblies. The head portion also includes a retractable trocar assembly which is slidably positioned within an anvil retainer and is automatically advanced and retracted upon attachment and detachment of the anvil assembly onto the anvil retainer. A lockout tube is provided and is positioned about an anvil retainer for releasably engaging an anvil assembly. The lockout tube prevents inadvertent detachment of the anvil assembly from the anvil retainer. The surgical stapling device also includes a firing lockout assembly which prevents actuation of the firing trigger until an anvil has been attached to the device and the anvil has been approximated. In one preferred embodiment, the firing lockout assembly includes a trigger lock and a safety bracket which prevents movement of the trigger lock from a locked to an unlocked position until an anvil has been attached to the device and approximated and returns the trigger lock to a locked position after the device has been fired. A tactile indication mechanism is also provided for notifying a surgeon that the device has been fired and for notifying a surgeon that the anvil head has been unapproximated a distance sufficient to permit the anvil head to tilt.

This application is a divisional of U.S. application Ser. No. 10/472,402filed Sep. 17, 2003 now U.S. Pat. No. 6,945,444, which claims priorityfrom PCT application Ser. No. PCT/US02/10792 filed Apr. 3, 2002, whichclaims priority from provisional application Ser. Nos. 60/281,259, filedApr. 3, 2001, 60/327,653, filed Oct. 5, 2001 and 60/363,715, filed Mar.11, 2002, all of which are incorporated herein by reference in theirentirety.

BACKGROUND

1. Technical Field

The present disclosure relates generally to a surgical stapling devicefor applying surgical staples to body tissue. More particularly, thepresent disclosure relates to a surgical stapling device for performingcircular anastomosis of hollow tissue organs.

2. Background to Related Art

Anastomosis is the surgical joining of separate hollow organ sections sothat the sections intercommunicate with each other. Typically, theanastomosis procedure follows surgery in which a diseased or defectivesection of hollow tissue is removed and the remaining end sections areto be joined. Depending on the desired anastomosis procedure, the endsections may be joined by either circular, end-to-side or side-to-sideorgan reconstruction methods.

In a circular anastomosis procedure, the two ends of the organ sectionsare joined by means of a stapling instrument which drives a circulararray of staples through the end sections of each organ section andsimultaneously cores any overlapping tissue to free the tubular passage.Examples of instruments for performing circular anastomosis of holloworgans are described in U.S. Pat. Nos. 6,053,390, 5,588,579, 5,119,983,5,005,749, 4,646,745, 4,576,167, and 4,473,077. Typically, theseinstruments include an elongated shaft having a handle portion at aproximal end to actuate the instrument and a staple holding componentdisposed at a distal end. An anvil assembly including an anvil rod withattached anvil head is mounted to the distal end. Opposed end portion ofthe organs to be stapled are clamped between the anvil head and thestaple holding component. The clamped tissue is stapled by driving oneor more staples from the staple holding component so that the ends ofthe staples pass through the tissue and are deformed by the anvil head.

Generally, during an anastomosis procedure, the anvil assembly isseparated from the stapling device and positioned within the patient inone of the tissue sections and the stapling device is positioned withinthe other of the tissue sections. Thereafter, the anvil assembly and thestapling device are reattached to clamp the tissue sectionstherebetween. Typically, placement requires the use of a detachabletrocar for one or both of the anvil assembly and stapling instrument.Because of limitations on visibility and accessibility to the surgicalsite, it may be difficult and time consuming for a surgeon to attach anddetach a trocar to the anvil assembly and/or the stapling device.Moreover, it may be difficult to determine whether the anvil assemblyhas been properly reattached to the stapling device.

SUMMARY

In accordance with the present disclosure, a surgical stapling device isdisclosed for performing circular anastomoses. The surgical staplingdevice includes a handle portion, an elongated body portion and a headportion including an anvil assembly and a shell assembly. The handleportion includes a rotatable approximation knob for approximating theanvil and shell assemblies and a firing trigger for actuating a firingmechanism for ejecting staples positioned within the shell assembly. Thefiring trigger forms one link of a two bar linkage provided to actuatethe firing mechanism. The two bar linkage provides the device with animproved mechanical advantage to reduce the firing forces required tofire the device.

The head portion includes an anvil assembly including a tiltable anvilwhich will tilt automatically after firing of the device andunapproximating the anvil and shell assemblies. The tiltable anvilprovides a reduced anvil profile to simplify removal of the device afterthe anastomoses procedure has been performed. The head portion alsoincludes a retractable trocar assembly which is slidably positionedwithin an anvil retainer and is automatically advanced and retractedupon attachment and detachment of the anvil assembly onto the anvilretainer. The retractable trocar assembly simplifies the anastomosesprocedure by eliminating the step of attaching and detaching a trocar tothe stapling device. A lockout tube is provided and is positioned aboutan anvil retainer for releasably engaging an anvil assembly. The lockouttube prevents inadvertent detachment of the anvil assembly from theanvil retainer such as during firing of the stapling device after apredetermined degree of approximation.

The surgical stapling device also includes a firing lockout assemblywhich prevents actuation of the firing trigger until an anvil has beenattached to the device and the anvil has been approximated. In onepreferred embodiment, the firing lockout assembly includes a triggerlock and a safety bracket which prevents movement of the trigger lockfrom a locked to an unlocked position until an anvil has been attachedto the device and approximated. The lockout assembly also includes alockout sleeve for returning the trigger lock to a locked position afterthe device has been fired. The lockout assembly prevents a surgeon frominadvertently firing the device without an anvil attached and mistakenlyfiring a device which has already been fired and has no staples.

The surgical stapling device also includes tactile indication mechanism.In one preferred embodiment, the tactile indication mechanism notifies asurgeon that the device has been fired. In another prefired embodiment,the tactile indicator notifies a surgeon that the anvil head has beenunapproximated a distance sufficient to permit the anvil head to tilt,and thus, indicating that the device can be removed from the patient.

BRIEF DESCRIPTION OF THE DRAWINGS

Various preferred embodiments of the presently disclosed surgicalstapling device are disclosed herein with reference to the drawings,wherein:

FIG. 1 is an elevated side perspective view from the proximal end of oneembodiment of the presently disclosed surgical stapling device.

FIG. 2 is an elevated side perspective view from the distal end of thesurgical stapling device shown in FIG. 1;

FIG. 3 is an elevated side perspective view from the proximal end ofanother preferred embodiment of the presently disclosed surgicalstapling device;

FIG. 4 is an elevated side perspective view from the distal end of thesurgical stapling device shown in FIG. 3;

FIG. 5 is an elevated side perspective view from the proximal end ofanother preferred embodiment of the presently disclosed surgicalstapling device;

FIG. 6 is an elevated side perspective view from the distal end of thesurgical stapling device shown in FIG. 5;

FIG. 7 is an elevated side perspective view of the proximal end of thesurgical stapling device shown in FIG. 1 with a handle section removed;

FIG. 8 is an elevated side perspective view of the proximal end of thesurgical stapling device shown in FIG. 7 with parts separated;

FIG. 8A is an enlarged view of the indicated area of detail shown inFIG. 8;

FIG. 8B is an elevated side perspective view of the tactile indicator ofthe surgical stapling device shown in FIG. 8;

FIG. 9 is an elevated side perspective view of the central and distalportions of the surgical stapling device shown in FIG. 1 with partsseparated;

FIG. 9A is an elevated side perspective view of another preferredembodiment of the central and distal portions of the surgical staplingdevice shown in FIG. 1 with parts separated;

FIG. 9B is a side elevational view of the pusher link shown in FIG. 9A;

FIG. 9C is a top view of the pusher link shown in FIG. 9B;

FIG. 9D is a cross-sectional view of taken along section line 9D—9D ofFIG. 9C;

FIG. 9E is a cross-sectional view taken along section line 9E—9E of FIG.9B;

FIG. 9F is a cross-sectional view taken along section lines 9F—9F ofFIG. 9B;

FIG. 9G is a cross-sectional view taken along section lines 9G—9G ofFIG. 9B;

FIG. 9H is a cross-sectional view taken along section lines 9H—9H ofFIG. 9B;

FIG. 9J is a cross-sectional view taken along section lines 9J—9J ofFIG. 9B;

FIG. 9K is a cross-sectional view taken along section lines 9K—9K ofFIG. 9B;

FIG. 9L is a cross-sectional view of the elongated body of the surgicalstapling device shown in FIG. 1;

FIG. 9M is a top perspective view of the spacer of the surgical staplingdevice shown in FIG. 1;

FIG. 9N is a bottom perspective view of the spacer shown in FIG. 9M;

FIG. 10 is an enlarged view of the indicated area of detail shown inFIG. 9;

FIG. 11 is an elevated side perspective view of the screw and screw stopassembly and cam adjustment mechanism with parts separated of thesurgical stapling device shown in FIG. 1;

FIG. 11A is a side elevational partial cutaway view of the screw andscrew stop assembly of the surgical stapling device shown in FIG. 11;

FIG. 11B is a side elevational partial cutaway view of the screw andscrew stop assembly and cam adjustment mechanism shown in FIG. 11;

FIG. 11C is a side elevational partial cutaway view of the screw andscrew stop assembly and cam adjustment mechanism shown in FIG. 11 withthe cam adjustment mechanism being rotated in a counter-clockwisedirection;

FIG. 11D is a side elevational partial cutaway view of the screw andscrew stop assembly and cam adjustment mechanism shown in FIG. 11 withthe cam adjustment mechanism being rotated in a clockwise direction;

FIG. 12 is a top perspective view of the screw and screw stop assemblyand cam adjustment mechanism shown in FIG. 11;

FIG. 13 is a bottom perspective view of the screw and screw stopassembly and cam adjustment shown in FIG. 12;

FIG. 14 is an elevated side perspective view with parts separated of therotatable sleeve and firing lockout assembly of the surgical staplingdevice shown in FIG. 1;

FIG. 15 is an elevated side perspective view of the anvil assembly ofthe surgical stapling device shown in FIG. 1;

FIG. 15A is an elevated perspective view from the distal end of theanvil assembly of the surgical stapling device shown in FIG. 1;

FIG. 15B is a cross-sectional view of the proximal end of the anvilcenter rod of the surgical stapling device shown in FIG. 15;

FIG. 15C is a side cross-sectional view of a trocar positioned in thedistal end of the anvil center rod of the anvil assembly shown in FIG.15;

FIG. 16 is an elevated side perspective view with parts separated of theanvil assembly shown in FIG. 15;

FIG. 16A is a side cross-sectional view of the anvil assembly shown inFIG. 15;

FIG. 16B is a side cross-sectional view of the anvil assembly shown inFIG. 15 with the backup plate and cutting ring advanced distally;

FIG. 17 is an elevated side perspective view from the distal end of therotatable sleeve and firing lookout assembly shown in FIG. 14;

FIG. 18 is an elevated side perspective view from the proximal end ofthe rotatable sleeve and firing lockout assembly shown in FIG. 14;

FIG. 19 is a side elevational view with a handle section removed of thesurgical stapling device shown in FIG. 1 prior to attachment of theanvil assembly;

FIG. 19A is a side view with the handle section removed of the proximalend of the surgical stapling device shown in FIG. 19;

FIG. 19B is a side cross-sectional view of the surgical stapling deviceshown in FIG. 19;

FIG. 19C is an enlarged view of the indicated area of detail shown inFIG. 19B;

FIG. 19D is an enlarged view of the indicated area of detail shown inFIG. 19B;

FIG. 19E is a side view of the proximal end of the surgical staplingdevice shown in FIG. 19 with the handle sections removed;

FIG. 19F is a top perspective view of the proximal end of the surgicalstapling device shown in FIG. 19 with the handle sections removed;

FIG. 19G is a bottom perspective view of a portion of the proximal endof the surgical stapling device shown in FIG. 19 with the handlesections removed;

FIG. 19H is a cross-sectional view taken along section lines 19H—19H ofFIG. 19D;

FIG. 20 is a side elevational view with a handle section removed of thesurgical stapling device shown in FIG. 1 with the anvil assemblyattached;

FIG. 20A is a side view with a handle section removed of the proximalend of the surgical stapling device shown in FIG. 20;

FIG. 20B is an elevated side cross-sectional view of the surgicalstapling device shown in FIG. 20;

FIG. 20C is an enlarged view of the indicated area of detail shown inFIG. 20B;

FIG. 20D is an enlarged view of the indicted area of detail shown inFIG. 20B;

FIG. 20E is a side view of the proximal end of the surgical staplingdevice shown in FIG. 20 with the handle sections removed;

FIG. 20F is a top perspective view of the proximal end of the surgicalstapling device shown in FIG. 20 with the handle sections removed;

FIG. 20G is a side cross-sectional view of the distal end of the shellassembly and the anvil assembly as shown in FIG. 1 prior to attachmentof the anvil assembly to the anvil retainer;

FIG. 20H is a side cross-sectional view of the distal end of the shellassembly and the anvil assembly shown in FIG. 20G during attachment ofthe anvil assembly to the anvil retainer;

FIG. 20J is a side cross-sectional view of the distal end of the shellassembly and the anvil assembly shown in FIG. 20G with the anvilassembly attached to the anvil retainer;

FIG. 20K is a enlarged view of the indicated area of detail shown inFIG. 20J;

FIG. 21 is a side elevational view with a handle section removed of thesurgical stapling device shown in FIG. 1 with the anvil assembly in theapproximated position;

FIG. 21A is a side view with a handle section removed of the proximalend of the surgical stapling device shown in FIG. 21;

FIG. 21B is a side cross-sectional view of the surgical stapling deviceshown in FIG. 21;

FIG. 21C is an enlarged view of the indicated area of detail shown inFIG. 21B;

FIG. 21D is an enlarged view of the indicated area of detail shown inFIG. 21B;

FIG. 21E is a side view of the proximal end of the surgical staplingdevice shown in FIG. 20 with the handle sections removed;

FIG. 21F is a top perspective view of the proximal end of the surgicalstapling device shown in FIG. 21 with the handle sections removed;

FIG. 21G is a bottom perspective view of a portion of the proximal endof the surgical stapling device shown in FIG. 21 with the handlesections removed;

FIG. 21H is a perspective cross-sectional view of the distal end of thesurgical stapling device shown in FIG. 21;

FIG. 22 is a side elevational view with a handle section removed of thesurgical stapling device shown in FIG. 1 with the anvil assemblyattached and the firing trigger actuated;

FIG. 22A is a side view with a handle section removed of the proximalend of the surgical stapling device shown in FIG. 22;

FIG. 22B is a side cross-sectional view of the surgical stapling deviceshown in FIG. 22;

FIG. 22C is an enlarged view of the indicated area of detail shown inFIG. 22B;

FIG. 22D is an enlarged view of the indicated are of detail shown inFIG. 22B;

FIG. 22E is a side view of the proximal end of the surgical staplingdevice shown in FIG. 22 with the handle sections removed;

FIG. 22F is an enlarged view of the indicated are of detail in FIG. 22E;

FIG. 23 is a side elevational view with a handle section removed of thesurgical stapling device shown in FIG. 1 with the anvil assemblyattached after the device has been fired;

FIG. 23A is a side view with a handle section removed of the proximalend of the surgical stapling device shown in FIG. 23;

FIG. 23B is a side cross-sectional view of the surgical stapling deviceshown in FIG. 23;

FIG. 23C is an enlarged view of the indicated area of detail shown inFIG. 23B;

FIG. 23D is an enlarged view of the indicated area of detail shown inFIG. 23B;

FIG. 23E is a side view of the proximal end of the surgical staplingdevice shown in FIG. 23E with the handle sections removed;

FIG. 23F is a top perspective view of the proximal end of the surgicalstapling device shown in FIG. 23 with the handle sections removed;

FIG. 23G is a bottom perspective view of a portion of the proximal endof the surgical stapling device shown in FIG. 23 with the handlesections removed;

FIG. 24 is a side elevational view with a handle section removed of thesurgical stapling device shown in FIG. 1 with the anvil assemblyunapproximated and the anvil head tilted;

FIG. 24A is a side view with a handle section removed of the proximalend of the surgical stapling device shown in FIG. 24;

FIG. 24B is a side cross-sectional view of the surgical stapling deviceshown in FIG. 24;

FIG. 24C is an enlarged view of the indicated area of detail shown inFIG. 24B;

FIG. 24D is an enlarged view of the indicated area of detail shown inFIG. 24B;

FIG. 24E is a side cross-sectional part phantom view of the distal endof the anvil assembly shown in FIG. 1 with the anvil head partiallytilted;

FIG. 24F is a side cross-sectional part phantom view of the distal endof the anvil assembly shown in FIG. 24E with the anvil head in a fullytilted position;

FIG. 24G is a side view of the proximal end of the surgical staplingdevice shown in FIG. 24;

FIG. 24H is an enlarged view of the tactile indicator and screw stop ofthe surgical stapling device shown in FIG. 1 during unapproximation ofthe anvil assembly at a location where the anvil head is able to fullytilt;

FIG. 25 is a front perspective view of one embodiment of the presentlydisclosed surgical stapling device in the unapproximated position;

FIG. 26 is a perspective view of the head portion of the surgicalstapling device shown in FIG. 25 in the approximated position;

FIG. 27 is a rear perspective view of the surgical stapling device shownin FIG. 25;

FIG. 28 is a top view of the surgical stapling device shown in FIG. 25;

FIG. 29 is a side view of the surgical stapling device shown in FIG. 25;

FIG. 30 is a side perspective view of the surgical stapling device shownin FIG. 25 with a section of the stationary handle removed;

FIG. 31 is a perspective, partial cutaway view of the surgical staplingdevice shown in FIG. 25 excluding the anvil assembly with the parts ofthe handle portion separated;

FIG. 31A is a perspective view of the rear link of the firing mechanismand the safety link of the surgical stapling device shown in FIG. 25;

FIG. 32 is a front, perspective, partial cutaway view of the surgicalstapling device shown in FIG. 25 with the stationary handle, trigger andindicator assemblies removed;

FIG. 32A is a rear, perspective view of the proximal portion of FIG. 32;

FIG. 33 is an enlarged view of the proximal portion of FIG. 32;

FIG. 34 is a perspective view with parts separated of the elongated bodyportion and the head portion, excluding the anvil, of the surgicalstapling device shown in FIG. 25;

FIG. 34A is an enlarged view of the indicated area of detail shown inFIG. 34;

FIG. 34B is an enlarged view of the indicated area of detail shown inFIG. 34;

FIG. 35 is a perspective view with parts separated of the proximal endof the pusher link and the indicator connector assembly,

FIG. 36 is a perspective view with parts separated of the distal portionof the approximation mechanism and the retractable trocar assembly ofthe surgical stapling device shown in FIG. 25;

FIG. 37 is a top, perspective view of the indicator assembly of thesurgical stapling device shown in FIG. 25;

FIG. 38 is a top, perspective view with parts separated of the indicatorassembly shown in FIG. 37;

FIG. 38A is a bottom perspective view of the indicator assembly shown inFIG. 37;

FIG. 39 is a perspective view of the trigger assembly of the surgicalstapling device shown in FIG. 25;

FIG. 40 is a perspective view with parts separated of the triggerassembly shown in FIG. 39;

FIG. 41 is a rear, perspective view of the anvil assembly of thesurgical stapling device shown in FIG. 25;

FIG. 42 is a front, perspective view of the anvil assembly shown in FIG.41;

FIG. 43 is a rear, perspective view of the anvil assembly shown in FIG.41 with a removable trocar attached to the anvil center rod;

FIG. 44 is a perspective view with parts separated of the anvil assemblyof the surgical stapling device shown in FIG. 25;

FIG. 45 is a side cross-sectional view of the anvil assembly andremovable trocar shown in FIG. 43 prior to attachment;

FIG. 46 is a side cross-sectional view of the anvil assembly andremovable trocar in the attached configuration;

FIG. 47 is a side view of the handle portion of the surgical staplingdevice shown in FIG. 25 prior to approximation and firing of the devicewith a section of the stationary handle removed;

FIG. 48 is a side cross-sectional view of the surgical stapling deviceshown in FIG. 25;

FIG. 49 is an enlarged view of the indicated area of detail shown inFIG. 48;

FIG. 49A is an enlarged view of the indicated area of detail shown inFIG. 49;

FIG. 50 is an enlarged view of the indicated area of detail shown inFIG. 48;

FIG. 51 is a side cross-sectional view of the head portion of thesurgical stapling device excluding the anvil assembly, with the trocarassembly in an extended position;

FIG. 52 is a side cross-sectional view taken along section lines 52—52in FIG. 50;

FIG. 53 is a side cross-sectional view of the distal end of the surgicalstapling device shown in FIG. 25 immediately prior to attachment of theanvil assembly to the anvil retainer;

FIG. 53A is a side cross-sectional view of the distal end of thesurgical stapling device shown in FIG. 25 during attachment of the anvilassembly to the anvil retainer;

FIG. 54 is a side cross-sectional view of the distal end of the surgicalstapling device shown in FIG. 25 with the anvil assembly spaced from theshell assembly;

FIG. 54A is an enlarged view of the indicated area of detail shown inFIG. 54;

FIG. 54B is an enlarged view of the indicated area of detail shown inFIG. 54;

FIG. 55 is a side cross-sectional view of the surgical stapling deviceshown in FIG. 25 with the anvil assembly and the shell assembly in theapproximated position;

FIG. 56 is an enlarged view of the indicated area of detail shown inFIG. 55;

FIG. 57 is an enlarged view of the indicated area of detail shown inFIG. 55;

FIG. 57A is an enlarged view of the indicated area of detail shown inFIG. 57;

FIG. 58 is a side cross-sectional view of the handle portion of thesurgical stapling device shown in FIG. 25, after the device has beenapproximated and during the beginning of the firing stroke of the firingtrigger;

FIG. 59 is a side cross-sectional view of the handle portion of thesurgical stapling device shown in FIG. 25 after the device has beenapproximated and during the end of the firing stroke of the firingtrigger;

FIG. 60 is a side cross-sectional view of the handle portion of thesurgical stapling device shown in FIG. 25 after the firing stroke of thefiring trigger;

FIG. 61 is a side cross-sectional view of the handle portion of thesurgical stapling device shown in FIG. 25 after the firing stroke of thefiring trigger with the trigger released;

FIG. 62 is a side cross-sectional view of the head portion of thesurgical stapling device shown in FIG. 25 in the approximated position;

FIG. 63 is a perspective view of the anvil assembly of the staplingdevice shown in FIG. 25 with the anvil head and anvil removed;

FIG. 64 is a side view of the anvil assembly of the stapling deviceshown in FIG. 25 with portions of the anvil head assembly in phantom;

FIG. 65 is a side cross-sectional view of the head portion of thesurgical stapling device shown in FIG. 25 during the firing stroke ofthe device;

FIG. 66 is a side view with parts in phantom of the anvil assemblyduring the firing stroke of the stapling device;

FIG. 67 is a side view of the anvil assembly shown in FIG. 66 with theanvil head assembly in a partially tilted position;

FIG. 68 is a side view of the anvil assembly shown in FIG. 66 in a fullytilted position;

FIG. 69 is a bottom perspective view of the indicator of the indicatorassembly of the surgical stapling device shown in FIG. 25;

FIG. 70 is a bottom view of the indicator of the indicator assembly ofthe surgical stapling device shown in FIG. 25;

FIG. 71 is a top view of the indicator arm of the indicator assembly ofthe surgical stapling device shown in FIG. 25;

FIG. 72 is a bottom view of the indicator plate of the indicatorassembly of the surgical stapling device shown in FIG. 25;

FIG. 73 is a top view of the indicator assembly of the surgical staplingdevice shown in FIG. 25 prior to anvil attachment and approximation ofthe device;

FIG. 74 is a top view of the indicator assembly of the surgical staplingdevice shown in FIG. 25 after the anvil assembly has been attached butprior to approximation of the device; and

FIG. 75 is a top view of the indicator assembly of the surgical staplingdevice shown in FIG. 25 after the anvil assembly has been attached andthe device has been approximated.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Preferred embodiments of the presently disclosed surgical staplingdevice will now be described in detail with reference to the drawings inwhich like reference numerals designate identical or correspondingelements in each of the several views.

FIGS. 1–6 illustrate one preferred embodiment of the presently disclosedsurgical stapling device shown generally as 10. Briefly, surgicalstapling device 10 includes a proximal handle portion 12, an elongatedcentral body portion 14 including a curved elongated outer tube 14 a,and a distal head portion 16. Alternately, in some surgical procedurese.g., the treatment of hemorrhoids, it is desirable to have asubstantially straight central body portion. See FIGS. 3 and 4.Moreover, the length and or the diameter of body portion 14 and headportion 16 may be varied to suit a particular surgical procedure. SeeFIGS. 5 and 6. Throughout this description, the term “proximal” willrefer to the portion of the instrument closest to the operator and theterm “distal” will refer to the portion of the instrument furthest fromthe operator.

Handle portion 12 includes a stationary handle 18, a firing trigger 20,a rotatable approximation knob 22 and an indicator opening 24.Stationary handle 18 is preferably formed from thermoplastic handlesections 18 a and 18 b, e.g., polycarbonate, which together define ahousing for the internal components of handle portion 12. Handlesections 18 a and 18 b are preferably secured together by sonic welding.Alternately, other known securement techniques may be employed includingscrews, adhesives, snap-fit connectors, etc. The internal components ofhandle portion 12 will be discussed in detail below. A cushioned and/orresilient slip resistant grip 19 is fastened to or included as part ofhandle sections 18 a and 18 b and firing trigger 20, preferably using anovermolding procedure. Grip 19 may be formed from neoprene or rubber.Alternately, other suitable materials and joining techniques may beemployed. A pivotally mounted trigger lock 26 is fastened to handleportion 12 and is manually positioned to prevent inadvertent firing ofstapling device 10. Indicator opening 24 defines an opening ortranslucent surface which facilitates viewing of an internallypositioned indicator which identifies whether stapling device 10 is in afire ready position or not.

Head portion 16 includes an anvil assembly 30 and a shell assembly 31.Each of these assemblies will be discussed in detail below. Except whereotherwise noted, the components of surgical device 10 are formed fromthermoplastics including polycarbonates and metals including stainlesssteel and aluminum. The particular material selected to form aparticular component will depend upon the strength requirements of theparticular component. For example, the anvil will be formed from ametal, such as stainless steel, and the stationary handle will be formedfrom a thermoplastic such as polycarbonate. Alternately, other materialsnot listed above, which preferably can withstand sterilizationprocedures, may be used to form components of stapling device 10provided the materials are suitable for surgical use and meet thestrength requirements of the particular component.

FIGS. 7 and 8 illustrate the internal components of handle portion 12 ofsurgical stapling device 10. Handle portion 12 houses an indicatormechanism, a lockout mechanism, the proximal components of anapproximation mechanism and a firing mechanism and other mechanisms forobtaining safe and effective operation of the surgical stapling device.Each of these mechanisms will be described in detail hereinbelow.

Approximation Mechanism

Referring to FIGS. 7–14, the approximation mechanism includesapproximation knob 22, a rotatable sleeve 33 (FIG. 14), a screw 32,first and second screw extensions 34 and 36 (FIG. 9), respectively, andanvil retainer assembly 38 (FIG. 10). Rotatable sleeve 33 includes asmall diameter cylindrical hollow body portion 40 and a large diameterhollow body portion 42. Body portions 40 and 42 define a central bore 33a. Body portion 42 includes an annular groove 44 dimensioned to receivean inwardly extending annular flange 46 (FIG. 7) formed on an internalwall of stationary handle 18. Engagement between groove 44 and flange 46axially fixes sleeve 30 within stationary handle 18 while permittingrelative rotation. The proximal end of hollow body portion 40 ofrotatable sleeve 33 extends through an opening formed in the proximalend of stationary handle 18 and includes diametrically opposed elongatedribs 48. Approximation knob 22 includes a cap 22 a and a body 22 bdefining a bore 49 having diametrically opposed elongated slots 49 aconfigured to receive ribs 48 of sleeve 30 such that rotation of knob 22effects concurrent rotation of sleeve 30.

The proximal end of screw 32 includes a helical channel 50 and isdimensioned to be slidably positioned within central bore 33 a ofrotatable sleeve 33. A pin 52 (FIG. 14) extends radially through bodyportion 42 of sleeve 33 into helical channel 50. Since sleeve 33 isaxially fixed with respect to stationary handle 18, rotation of sleeve33 about screw 32 causes pin 52 to move along channel 50 of screw 32 toeffect axial movement of screw 32 within stationary handle 18. Anaxially extending groove 32 a is formed along the distal portion ofscrew 32. Groove 32 a is dimensioned to receive an indicator link orwire as will be described below.

The distal end of screw 32 includes a transverse slot 54. Top and bottomscrew extensions 34 and 36 (FIG. 9) each include a proximally locatedflexible flat band portion 58 and a distally located flat band portion60. The flexibility of top and bottom screw extensions 34 and 36 permitsmovement of screw extensions 34 and 36 through curved elongated bodyportion 14. The proximal end of each band portion 58 includes a hole 62dimensioned to receive a pin 64 for securing the proximal end of screwextensions 34 and 36 within transverse slot 54 of screw 32. Alternately,other fastening techniques may be used to secure each band portion 58 toscrew 32, e.g., welding, crimping, etc. Distally located band portion 60of each screw extension 34 and 36 is dimensioned to be received within atransverse slot 66 formed in a proximal end of anvil retainer 38 (FIG.10) to fasten anvil retainer 38 to the distal end of screw extensions 34and 36. Preferably, band portion 60 is brazed or welded within slot 66.Alternately, other fastening techniques may be used including screws,crimping, etc. The distal end of anvil retainer 38 includes a pluralityof flexible legs 70 which are configured to flex outwardly to receiveand engage the anvil assembly as will be discussed in further detailbelow.

In operation, when approximation knob 22 is manually rotated, rotatablesleeve 33 is rotated about the proximal end of screw 32 to move pin 52along helical channel 50 of screw 32. Since sleeve 33 is axially fixedto stationary handle 18, as pin 52 is moved through channel 50, screw 32is advanced or retracted within stationary handle 18. As a result, topand bottom screw extensions 34 and 36, which are fastened to the distalend of screw 32, and anvil retainer 38, which is fastened to the distalend of screw extensions 34 and 36, are moved axially within elongatedbody portion 14. Since anvil assembly 30 is secured to the distal end ofanvil retainer 38, rotation of approximation knob 22 will effectmovement of anvil assembly 30 in relation to shell assembly 31 betweenspaced and approximated positions.

Firing Mechanism

Referring to FIGS. 7–9, the firing mechanism includes firing trigger 20,a firing link 72 and an elongated pusher link 74. Firing trigger 20includes a body portion 76 and a trigger cover 80. A cushioned grippingsurface 82 preferably formed of neoprene or rubber is provided ontrigger cover 80. Cushioned gripping surface 19 provides a non-slipcushioned surface to make actuation of device 10 more comfortable to asurgeon. Body portion 76 of trigger 20 is pivotally connected to acoupling member 86 secured to the proximal end of pusher link 74 by apivot member 84. Coupling member 86 may be formed integrally with pusherlink 74 or as a separate element fastened thereto. Firing link 72 has afirst end pivotally secured to body portion 76 of trigger 20 by a pivotmember 87 and a second end pivotally secured within a vertical slot 82formed between stationary handle half-sections 18 a and 18 b ofstationary handle 18 by pivot member 79. Pivot member 79 is free to movevertically within slot 82. A spring 82 a is supported within handle 18to urge pivot member 79 downwardly towards the bottom of slot 82. Bodyportion 76 further includes a pair of abutments including an abutment 89and an abutment 91 which are positioned to engage the distal end oftrigger lock 26 in a manner to be described in greater detail below toprevent actuation of trigger 20 prior to approximation of device 10 andafter device 10 has been fired. A projection 93 is also formed on bodyportion 76 of firing trigger 20 and is configured to activate a triggerlock return mechanism of a firing lockout mechanism of surgical staplingdevice 10 as will be described below.

Coupling member 86 which is supported on the proximal end of elongatedpusher link 74 includes a flange 104 (FIG. 9). A spring 106, positionedbetween an inner wall or abutment within stationary handle 18 and flange104, biases pusher link 74 proximally to a retracted, non-firedposition. A pair of wings 108 extend radially outwardly from couplingmember 86. Wings 108 are dimensioned to slide along slots 111 (FIG. 8)formed along the internal walls of stationary handle 18 to maintainproper alignment of pusher link 74 within stationary handle 18 duringfiring of device 10.

The distal end of pusher link 74 includes a pair of engagement fingers110 which are dimensioned to lockingly engage with members 220 formed inthe proximal end of pusher back 186. Pusher back 186 forms part of shellassembly 31 and will be discussed in greater detail below. Pusher link74 is preferably formed from a flexible plastic material and can includea plurality of notches 187 which allow the pusher link to bend moreeasily as it moves through body 14. Pusher link 74 defines a hollowchannel 75 for slidably receiving the approximation mechanism. A flatsurface or cutout 74 a slidably supports screw extensions 34 and 36. Aspacer 77 is positioned within outer tube 14 a adjacent cutout 74 a toprovide additional support for screw extensions 34 and 36 and pusherlink 74 to prevent each component from buckling during actuation. Anannular channel 74 b is formed about pusher link 74 to receive an O-ringseal 74 c. Pusher link 74 is slidably positioned within body portion 14such that O-ring 74 c seals the space between pusher link 74 and aninternal wall of body portion 14. Operation of the firing mechanism ofthe device will be described in detail below.

FIG. 9A illustrates a preferred embodiment of the firing mechanism ofthe presently disclosed surgical stapling device. In FIG. 9A, pusherlink 74′ is modified to reduce the amount of material from which thepusher link is made and yet reduce the bending moment of the pusher linkand, accordingly the force required to actuate the firing mechanism.Referring also to FIGS. 9B–9E, pusher link 74′ includes a curved bodyportion having upper and lower flats 74 a′ and 74 b′ and distal andproximal annular end sections 74 f and 74 e′. A slot 74 c′ is formed inupper flat 74 a′ and is dimensioned to receive an indicator link or wireas will be described in further detail below. Upper flat 74 a′ isdimensioned to slidably support screw extensions 34 and 36. Spacer 77,as discussed above, is positioned adjacent upper flat 74 a′ to abutscrew extensions 34 and 36 (FIG. 9L). Pusher link 74′ includes a pair ofsidewalls 74 d′ which confine screw extensions 34 and 36. As shown inFIG. 9D, preferably sidewalls 74 d′ extend the length of upper flat 74a′ and communicates with annular end sections 74 e′ and 74 f of pusherlink 74′. Sidewalls 74 d′ convey compressive force in order to balanceor equalize the compressive force exerted along pusher link 74′ in theportions of the pusher link' relative to the portions thereof above andbelow the centerline of outer tube 14 a.

When firing trigger 20 is actuated, i.e., pivoted about pivot member 84,firing link 72 is moved proximally until pivot member 79 engages anabutment surface 307 (FIG. 11A–D) formed on screw stop 306. Thereafter,firing trigger 20 is pushed distally to advance pusher link 74 or 74′distally against the bias of spring 106. Since the distal end of pusherlink 74 or 74′ is connected to pusher back 186, actuation of firingtrigger 20 effects advancement of pusher back 186 within shell assembly31 to eject staples from shell assembly 31 in a manner to be describedbelow.

Anvil Assembly

Referring to FIGS. 15–16A, anvil assembly 30 includes an anvil headassembly 120 and an anvil center rod assembly 152. Anvil head assembly120 includes a post 122, an anvil head 124, a backup plate 126, acutting ring 128 and an anvil 129. Anvil head 124 includes an innerannular recess 134 and an outer annular recess 136. Post 122 iscentrally located within inner annular recess 134 of anvil head 124.Anvil 129 is supported on anvil head 124 in annular recess 136 andincludes a plurality of pockets 140 for receiving and deforming staples.Backup plate 126 includes a central opening 126 b which is positionedabout post 122 within recess 134 defined between post 122 and annularrecess 136. Backup ring 126 includes a raised platform 126 a. Cuttingring 128 includes an opening 128 a having a configuration substantiallythe same as platform 126 a. Opening 128 a is positioned about platformto rotatably fix cutting ring 128 a on backup ring 126. Preferably,cutting ring 128 is formed from polyethylene and is fixedly secured tobackup plate 126 using, for example, an adhesive. Backup ring 126 ispreferably formed from metal. Alternately other materials ofconstruction may be used to construct plate 126 and ring 128. Cuttingring 126 and backup plate 148 are slidably mounted about post 122.Backup plate 126 includes a pair of inwardly extending tabs 150 whichwill be described in further detail below.

Anvil center rod assembly 152 includes anvil center rod 154, a plunger156 and plunger spring 158. A first end of center rod 154 includes atransverse throughbore 160 which is spaced radially of a centrallongitudinal axis of center rod 154. Post 122 of anvil head assembly 120also includes a transverse throughbore 162. A pivot member 164 pivotablysecures post 122 to center rod 154 such that anvil head assembly 120 ispivotably mounted to anvil center rod assembly 152. Plunger 156 isslidably positioned in a bore 154 b (FIG. 16A) formed in the first endof center rod 154. Plunger 156 includes an engagement finger 168 whichis offset from the pivot axis of anvil head assembly 120 and biased intoengagement with the base 122 a of post 122 by plunger spring 158 to urgeanvil head assembly 120 to a pivoted position. In a prefired position,tabs 150 formed on backup plate 126 engage a top surface 154 a (FIG.16B) of center rod 154 to prevent anvil head assembly 120 from pivotingabout pivot member 164. As device 10 is being fired, backup plate 126and cutting ring 128 are moved deeper into anvil recess 134 of anvilhead 124 about post 122 (FIG. 16B) by knife 188 (FIG. 9) in a manner tobe described in further detail below to move tabs 150 out of engagementwith top surface 154 a of center rod 154 to permit plunger 156 to pivotanvil head assembly 120 about pivot member 164.

A second end of center rod 154 includes a blind bore 170 (FIG. 15B)which includes an inwardly tapering opening 170 a and a spaced annularrecess 170 b. Blind bore 170 is dimensioned to receive a removabletrocar 157 (FIG. 15C). The annular recess is positioned within blindbore 170 and dimensioned to receive an annular rib formed on the trocar(not shown) to secure center rod 154 in engagement with the trocar.Alternately, trocar 157 may be retained within center rod 154 using onlya suture 157 a, i.e., no frictional contact is provided between trocar157 and center rod 154. This allows for easy removal of trocar 157 fromcenter rod 154 (FIG. 15C). The outer surface of center rod 154 includesan annular abutment 175 which defines an annular recess 177. Annularrecess 177 is dimensioned to engage legs 70 of anvil retainer 38 toreleasably secure anvil assembly 30 to anvil retainer 38. A bore 179extends transversely through center rod 154 and is dimensioned toreceive a suture for securing a trocar to the center rod. A collar 181including a plurality of splines 181 a is secured about center rod 154.Splines 181 a function to align anvil assembly 30 with shell assembly 31during approximation of the anvil and shell assemblies.

Shell Assembly

Referring to FIG. 9, shell assembly 31 includes a shell 182, a pusherback 186, a cylindrical knife 188, and a staple guide 192. Shell 182includes an outer housing portion 194 and an inner guide portion 196.Outer housing portion 194 defines a throughbore 198 having a distalcylindrical section 200, a central conical section 202 and a proximalsmaller diameter cylindrical section 204. A plurality of openings 206are formed in conical section 202. Openings 206 are dimensioned topermit fluid and tissue passage during operation of the device. A pairof diametrically opposed flexible engagement members 207 are formed onproximal cylindrical section 204 of shell 182. Engagement members 207are positioned to be received in openings 209 formed on the distal endof elongated body 14 to secure shell 182 to elongated body 14. A pair ofopenings 211 are formed in the proximal end of outer tube 14 a. Openings211 are dimensioned to receive protrusions (not shown) formed on theinternal wall of stationary handle 18 to facilitate attachment of tube14 a to handle portion 12.

Pusher back 186 includes a central throughbore 208 which is slidablypositioned about inner guide portion 196 of shell 182. Pusher back 186includes a distal cylindrical section 210 which is slidably positionedwithin distal cylindrical section 200 of shell 182, a central conicalsection 212 and a proximal smaller diameter cylindrical section 214. Theproximal end of pusher back 186 includes members 220 which areconfigured to lockingly engage with resilient fingers 110 of pusher link74 to fasten pusher link 74 to pusher back 186 such that a distal faceof pusher link 74 abuts a proximal face of pusher back 186.

The distal end of pusher back 186 defines a pusher 190. Pusher 190includes a multiplicity of distally extending fingers 226 dimensioned tobe slidably received within slots 228 formed in staple guide 192 toeject staples 230 therefrom. Cylindrical knife 188 is frictionallyretained within the central throughbore of pusher back 186 to fixedlysecure knife 188 in relation to pusher 190. Alternately, knife 188 maybe retained within pusher back 186 using adhesives, crimping, pins, etc.The distal end of knife 188 includes a circular cutting edge 234.

In operation, when pusher link 74 is advanced distally in response toactuation of firing trigger 20, as will be described below, pusher back186 is advanced distally within shell 182. Advancement of pusher back186 advances fingers 226 through slots 228 of staple guide 192 toadvance staples 230 positioned within slots 228 and eject staples 230from staple guide 192. Since knife 188 is secured to pusher back 186,knife 188 is also advanced distally to core tissue as will be describedin more detail below.

Cam Adjustment Mechanism

Referring to FIGS. 11–13, a cam adjustment member 400 is secured by setscrew 312 onto a sidewall 306 a of screw stop 306, within a recess 306 bformed in sidewall 306 a. Cam adjustment member 400 includes a circulardisc 402 having a throughbore 404. Throughbore 404 is eccentricallyformed through disc 402 and is dimensioned to receive set screw 312. Asmaller notch or hole 406 is also formed in disc 402. Notch 406 isdimensioned to receive the tip of an adjustment tool (not shown). Recess306 b (FIG. 11A) includes a forward and a rear shoulder or abutmentsurface 306 c and 306 d, respectively, and is dimensioned to receivedisc 402 such that the outer edge of disc 402 abuts forward and rearshoulders 306 c and 306 d.

As discussed above, set screw 312 extends through disc 402 and screwstop 306 and engages screw 32 to secure screw stop 306 in an axiallyfixed position on screw 32. Cam adjustment member 400 functions toadjust the axial position of screw stop 306 on screw 32. Morespecifically, set screw 312 can be loosened to allow disc 402 to rotatewithin recess 306 b of screw stop 306 while still remaining axiallyfixed to screw 32. Since disc 402 is eccentrically mounted about screw32 and engages forward and rear shoulders 306 c and 306 d of recess 306b, rotation of disc 402 about fixed set screw 312 will urge screw stop306 axially along screw 32 to adjust the axial position of screw stop306 on screw 32. For example, when disc 402 is rotated in a clockwisedirection (as viewed in FIG. 11D) identified by arrow “A”, screw stop306 will be moved axially in relation to screw 32 in the directionindicated by arrow “B” in response to engagement between the outer edgeof disc 402 and rear shoulder 306 d of recess 306 b. Conversely, whendisc 402 is rotated in a counter-clockwise direction (as viewed in FIG.11C), identified by arrow “C”, screw stop 306 will be moved axially inrelation to screw 32 in the direction indicated by arrow “D” in responseto engagement between the outer edge of disc 402 and forward shoulder306 c of recess 306 b.

When stapling device 10 is in a fully approximated position, i.e., anvilassembly 30 and shell assembly 31 are brought into juxtaposed alignmentto define a tissue receiving clearance, screw stop 306 abuts againstbody portion 42 of the rotatable sleeve 33. In this position, anvilassembly 30 and shell assembly 31 will be spaced slightly to define thetissue receiving clearance. By providing cam adjustment member 400, thetissue receiving clearance can be selectively adjusted by adjusting theposition of screw stop 306 on screw 32 to be within a desired range.Preferably, cam adjustment member 400 permits adjustment of the tissuereceiving clearance of ±0.045 inches, although greater or lesseradjustment capabilities are also envisioned. Typically, adjustments tothe tissue receiving clearance will be made by the device manufacturer.A hole or opening (not shown) may be provided in handle portion 12(FIG. 1) to provide access to cam adjustment member 400.

Retractable Trocar Assembly

Referring to FIGS. 9 and 10, stapling device 10 includes a retractabletrocar assembly slidably positioned within anvil retainer 38. Theretractable trocar assembly includes a trocar assembly 240 and anengagement member 242. Engagement member 242 may be in the form of aspring clip, as shown. Alternately, other engagement members areenvisioned, e.g., spring loaded protrusions, etc. Trocar assembly 240includes a trocar body 240 a and trocar tip 240 b. Trocar body 240 a hasa slot 244 which extends through trocar body 240 a along a portion ofits length. Slot 244 is dimensioned to receive engagement member 242.Trocar tip 240 b is secured to trocar body 240 a using, for examplescrew threads. Alternately, other fastening techniques can be used tosecure trocar tip 240 b to trocar body 240 a. While trocar tip 240 a isshown rounded or blunt, other tip configurations are envisioned. Trocartip 240 b includes a pair of resilient legs 240 c which deform, i.e.,straighten out, as the trocar is pushed through tissue to ramp tissueover anvil retainer 38. By providing legs 240 c, tissue is less likelyto become caught on anvil retainer 38 during use.

As shown in FIG. 10, engagement member 242 includes a proximal bodyportion 246 and a pair of distally extending resilient legs 248. Eachleg 248 includes a tapered tip 250 and a proximally facing shoulder 252.A pin 254 is positioned through openings 256 and 258 formed in bodyportion 246 of member 242 and trocar 240, respectively, to secureengagement member 242 within slot 244 of trocar 240. Pin 254 alsoextends through an elongated slot 255 formed in anvil retainer 38, suchthat the distal and proximal surfaces of slot 255 function as stops todefine the fully advanced and fully retracted positions of theretractable trocar assembly. Legs 248 are formed of a resilient materialsuch as spring steel. Alternately, other materials including plasticsmay be used to form engagement member 242. In an unbiased position, legs248 of member 242 extend outwardly of slot 244 of trocar 240 and beyondthe outer diameter of anvil retainer 38 such that in the fully advancedposition of trocar 240, shoulders 252 of legs 248 engage a distal end 38a of anvil retainer 38 to retain the trocar 240 in the advancedposition. See FIGS. 19H and 20G.

Referring to FIGS. 20G–20K, when the anvil assembly 30 is attached toanvil retainer 38, anvil center rod 154 of anvil assembly 30 is slid inthe direction indicated by arrow “Z” in FIG. 20G over tapered tips 250of legs 248 of engagement member 242 to compress legs 248 inwardly (FIG.20H) into the confines of slot 244 (FIG. 10) such that trocar 240 andmember 242 move inside blind bore 170 of center rod 154. As anvilassembly 30 is forced about trocar 240, trocar 240 is moved from itsextended to its retracted position within anvil retainer 38. Asillustrated, pin 254 moves from a first end 255 a of slot 255 to asecond end 255 b of slot 255.

When the anvil assembly is disengaged from anvil retainer 38 by pullingthe anvil assembly in a direction away from anvil retainer 38, legs 248of member 242 flex outwardly to move shoulders 252 of legs 248 of member242 into annular recess 170 b of center rod 154 (See FIG. 20K). As aresult, as anvil assembly 30 is disengaged from anvil retainer 38,engagement member 242 and thus trocar 240 are pulled distally to movetrocar 240 to the advanced position. As discussed above, in the advancedposition shoulders 252 of engagement member 242 engage the distal face38 a of anvil retainer 38.

The proximal end of trocar 240 includes a transverse slot 241 (FIG. 10).A rigid flexible indicator link or wire 243 has a distal end which issecured within slot 241 of trocar 240 and extends rearwardly throughelongated body portion 14 within slot 74 c (FIG. 9) of pusher link 74and along slot 32 a (FIG. 12) in screw 32 into handle portion 12 ofstapling device 10. Wire 243 has a proximal end which is secured to anindicator assembly in handle portion 12 which will be discussed indetail below.

Lockout Tube Assembly

Referring again to FIGS. 9 and 10, a cylindrical lockout tube 270 isslidably positioned about the outer surface of anvil retainer 38 andpositioned to extend through inner guide portion 196 of shell 182 andcentral bore 208 of pusher back 186. The proximal end of lockout tube270 includes an annular flange 272. A cylindrical fitting 273 is securedabout the proximal end of lockout tube 270 in the proximal end of bore208 of pusher back 186. A biasing member 187 engages flange 272 andurges lockout tube 270 distally to a position in which flange 272engages fitting 273 (FIG. 20D). Biasing member 187 is preferably atorsion spring which is positioned in compression between flange 272 oflockout tube 270 and an abutment formed within pusher link 74.

Lockout tube 270 is positioned about flexible legs 70 of anvil retainer38 to provide rigidity to legs 70 during approximation of the anvil andcartridge assemblies. Initially, prior to approximation, legs 70 ofanvil retainer 38 project from lockout tube 270. Accordingly, legs 70are free to flex outwardly to allow attachment and detachment of anvilassembly 30 to anvil retainer 38. During approximation, legs 70 arewithdrawn into lockout tube 270 to clamp legs 70 about center rod 154 ofthe anvil and prevent removal of the anvil assembly from the anvilretainer. Anvil retainer 38 is withdrawn into lockout tube 270 duringapproximation until shoulder 38 b of anvil retainer 38 engages distalface 270 a of lockout tube 270. Thereafter, both anvil retainer 38 andlockout tube 270 are retracted against the bias of spring 187 into bore208 of pusher back 186.

Indicator Assembly

Referring to FIGS. 7, 8 and 11–13, an indicator assembly is mountedwithin stationary handle 18 and includes an indicator plate 500 havingan engagement member 501 and indicia (not shown) formed thereon. Theindicia is preferably in the form of colored dots which identify whetherthe device 10 is in a fire-ready condition or not. For example, a greendot may indicate a fire-ready position and a red dot may indicate a firenot ready position. Alternately, other forms of indicia may be usedincluding graphic, written or numeric indicia. Indicator plate 500 isslidably positioned within stationary handle 18 such that the indicia isvisible through indicator opening 24. A biasing member 502, preferably acoil spring, is secured at one end to an inner wall of stationary handle18 and at the other end to indicator plate 500. Biasing member 502 ispositioned in tension to urge indicator plate 500 to its forward-mostposition within stationary handle 18.

A retainer slide 506 is slidably positioned within a pair of grooves 508formed in screw stop 306 and includes a first abutment surface 509 and asecond abutment surface 510. A substantially rigid indicator link orwire 243 extends from the proximal end of trocar body 240 a (FIG. 10)and is connected to retainer slide 506 by a set screw 512. Alternately,other fastening techniques may be employed. Wire 243 translates linearmovement of trocar assembly 240 into linear movement of retainer slide506 when an anvil assembly is being attached to anvil retainer 38.Accordingly, when anvil assembly 30 is attached to anvil retainer 38 tomove trocar 240 from its advanced position to its retracted position,wire 243 effects movement of retainer slide 506 from its forward-mostposition on screw stop 306 (FIG. 12) to its rearward-most position.

As discussed above, screw stop 306 is secured to screw 32 by set screw312. When approximation knob 22 is rotated to retract screw 32 intosleeve 30, screw stop 306 is retracted towards sleeve 30. After anvilassembly 30 has been attached to anvil retainer 38 and screw 32 has beenretracted a predetermined distance, first abutment surface 509 abutsengagement member 501 of indicator plate 500 such that furtherapproximation moves indicator plate 500 against the urging of biasingmember 502 to its rearward-most position. In its rearward-most position,the indicia on plate 500 is visible through opening 24 and identifiesthat device 10 is in a fire-ready condition.

It is noted that if device 10 is approximated without an anvil assembly30 attached to the anvil retainer 38, retainer slide 506 will remain inits forward-most position on screw stop 306, abutment surface 509 ofretainer slide 506 will not be in position to contact engagement member501 of indicator plate 500 during approximation of the device and theindicator assembly will remain in a fire-not ready position andindicated as such through opening 24.

Fire Lockout Assembly

Referring to FIGS. 8, 14, 17, and 18, a firing lockout assembly isprovided which includes trigger lock 26 (FIGS. 1 and 8), safety bracket520, a lockout sleeve 522 and a compression member 523. Safety bracket520 includes a forward collar portion 524, a body portion 526 having anelongated slot 528 and a rear C-shaped portion 530. Forward collarportion 524 is positioned about the proximal end of screw 32 adjacentand forward of body portion 42 of rotatable sleeve 30. Compressionmember 523 includes a plurality of fins 532 which partially define anannular channel 534. C-shaped portion 530 is positioned within annularchannel 534 of compression member 523. A biasing member 536, preferablya coil spring, is positioned in stationary handle 18 behind compressionmember 523 to urge compression member 523 and safety bracket 520forwardly within stationary handle 18.

Trigger lock 26 (FIG. 8) is pivotally supported between handle sections18 a and 18 b about pivot member 540 and includes an integrally formedlocking portion 542 positioned adjacent pivot member 540. When device 10is in the unapproximated position, body portion 526 of safety bracket520 is positioned adjacent or juxtaposed locking portion 542 of triggerlock 26 to prevent trigger lock 26 from pivoting about pivot member 540from its locking position (FIG. 1).

When device 10 is approximated, retainer slide 506 (FIG. 11) moves withscrew stop 306 to a position in which second abutment surface 510engages forward collar portion 524 of safety bracket 520 to move safetybracket 520 rearwardly. In the rearward position of safety bracket 520,elongated slot 528 is aligned with locking portion 542 of trigger lock26 to allow trigger lock 26 to be pivoted away from trigger 20 towardsstationary handle 18 and permit actuation of firing trigger 20.

It is noted that if an anvil has not been attached to device 10 andretainer slide 506 is in its forward-most position on screw stop 306,second abutment surface 510 will not be in position to engage forwardcollar portion 524 of safety bracket 520, locking portion 542 will abutbody portion 526 of safety bracket 520, and trigger lock 26 will not bepivotable to an unlocked position.

Lockout sleeve 522 includes a cylindrical portion 550, asemi-cylindrical body portion 552 and a forwardly extending arm 554. Aflexible tab 556 extends downwardly from arm 554 and includes aretaining surface 556 a. A drive member 558 extends downwardly from oneend of tab 556. Lockout sleeve 522 is positioned about rotatable sleeve33. A biasing member 560 which is preferably a torsion spring ispositioned to urge lockout sleeve 522 rearwardly within stationaryhandle 18. Lockout sleeve 522 also includes side fins 563 which arereceived within grooves within stationary handle 18 to confine lockoutsleeve 522 to linear movement.

When lockout sleeve 522 is positioned within stationary handle 18,biasing member 560 is compressed between body portion 42 of rotatablesleeve 33 and cylindrical portion 550 of lockout sleeve 522. Retainingsurface 556 a of flexible tab 556 is positioned to engage a surface 562(FIG. 19C) within stationary handle 18 such that biasing member 560 ismaintained in compression.

In operation, when firing trigger 20 is actuated, a projection 93(FIG. 1) formed on trigger actuator 20 moves into engagement with drivemember 558 to disengage retaining surface 556 a of tab 556 from surface562 within stationary handle 18. When this occurs, spring 560 moveslockout sleeve 522 rearwardly such that a portion of sleeve 522 engageslocking portion 542 of trigger lock 26 to pivot trigger lock 26 from anunlocked position to a locked position. In this post fire lockedposition, the distal end of trigger lock 26 returns to a positionbetween abutments 89 and 91 to again prevent the inadvertent firing ofdevice 10.

Tactile Indication

Referring to FIGS. 8, 8A, 8B, and 11, a tactile indicator 580 ispositioned within stationary handle 18 and is movable within a verticalslot 582 between retracted and extended positions. Tactile indicator 580includes a protrusion 580 a which is configured to be received withinone of two recesses 582 a and 582 b formed in slot 582. In the extendedposition, tactile indicator 580 is positioned to engage a wing 584formed on screw stop 306 at a position of unapproximation sufficient topermit the tilt anvil assembly to have tilted. Prior to firing device10, tactile indicator 580 is in the retracted position with protrusion580 a positioned within recess 582 a. When device 10 is fired, anabutment surface 588 formed on firing link 72 (FIG. 8) engages indicator580 to move indicator 580 to the extended position such that protrusion580 a is positioned in recess 582 a. When device 10 is unapproximated adistance sufficient to allow the anvil head to pivot, wing 584 of screwstop 306 engages indicator 580 to provide an audible and/or tactileindication that such a point of unapproximation has been reached.Thereafter, a surgeon can remove the device from the patient. In orderto remove the anvil assembly from the anvil retainer, after it has beenremoved from the patient the surgeon needs to further unapproximate thedevice further by providing a force to approximation knob 22 sufficientto urge tactile indicator 580 from the extended to the retractedposition.

Operation of surgical stapling device 10 will now be described in detailwith reference to FIGS. 19–24F.

FIGS. 19–19H illustrate surgical stapling device 10 in theunapproximated or open position prior to attachment of anvil assembly 30(FIG. 1) to anvil retainer 38. In this position, screw stop 306 ispositioned adjacent coupling 86 which is secured to the proximal end ofpusher link 74 and retainer slide 506 is located in its forward-mostposition on screw stop 306. Pusher link 74 is urged by spring 106 to itsretracted position. Body portion 526 of safety bracket 520 of the firelockout assembly is urged by spring 560 to a position to prevent triggerlock 26 from pivoting. See FIG. 19C. Pivot member 79 secured to firinglink 72 is positioned in the base of vertical slot 82 by biasing member82 a (FIG. 19E). Tactile indicator 580 is in its retracted position withprotrusion 580 a positioned within detent 582 a.

Referring to FIGS. 19D and 19H, as discussed above, prior to attachmentof anvil assembly 30 to anvil retainer 38, trocar assembly 240 is in itextended position with trocar tip 240 b extending outwardly from anvilretainer 38. Shoulders 252 of engagement member legs 248 abut againstdistal face 38 a of anvil retainer 38 to prevent trocar assembly 240from being forced to its retracted position.

FIGS. 20–20F illustrate surgical stapling device 10 having anvilassembly 30 secured to anvil retainer 38 and in the unapproximated oropen position. Referring to FIG. 20D, when anvil assembly 30 is attachedto anvil retainer 38, anvil center rod 154 is positioned over trocar tip240 b and pushed into anvil retainer 38. When this occurs, legs 248 ofengagement member 242 are compressed inwardly to disengage shoulder 252of legs 248 from engagement with distal face 38 a of anvil retainer.This allows center rod 154 to be inserted into anvil retainer 38 untilthe distal ends of flexible legs 70 of anvil retainer 38 are receivedwithin annular recess 177 of anvil center rod 154. As this happens,trocar assembly 240 is moved to its retracted position with pin 254positioned at the proximal end of slot 255 in anvil retainer 38.

As the trocar assembly is moved to the retracted position, indicatorlink or wire 243 (FIGS. 11 and 12) moves retainer 506 from itsforward-most position on screw stop 306 to its rearward-most position.In the rearward-most position, upon approximation of device 10, firstabutment surface 509 of retainer slide 506 will engage member 501 ofindicator plate 500 and abutment surface 510 will engage forward collarposition 524 of safety bracket 520. The remaining components of device10 are not affected by attachment of anvil assembly 30 to anvil retainer38.

FIGS. 21–21G illustrate surgical stapling device 10 with an anvilassembly 30 attached to anvil retainer 38 in the approximated position.As discussed above, anvil assembly 30 is moved to the approximatedposition from the unapproximated position shown in FIG. 20 by rotatingrotation knob 22. Rotation of knob 22 causes rotation of cylindricalsleeve 33 which rotates pin 52 within helical channel 50 of screw 32.Since sleeve 33 is axially fixed, movement of pin 52 within helicalchannel 50 effects linear retraction of screw 32 into hollow sleeve 33.The distal end of screw 32 is connected to screw extensions 34 and 36which are fastened at their distal ends to anvil retainer 38 such linearmovement of screw 32 is translated into linear movement of anvilretainer 38 and anvil assembly 30.

Screw stop 306 is secured to screw 32 by set screw 312. Thus, duringapproximation of device 10, screw stop 306 is moved from a forwardposition within handle 18 (FIG. 20) to a rearward position within handle18 (FIG. 21). As screw stop 306 is moved from its forward-most positionto its rearward-most position, first abutment member 509 on retainerslide 506 engages member 501 of indicator plate 500 and abutment member510 on retainer slide 506 engages collar portion 524 of safety bracket520 to move indicator plate 500, against the bias of spring 502, andsafety bracket 520, against the bias of spring 536, rearwardly withinhandle 18. Movement of indicator plate 500 rearwardly positions thefire-ready indicia beneath indicator opening 24. Movement of safetybracket 520 rearwardly aligns elongated slot 528 in body 526 of safetybracket 520 with locking portion 542 of trigger lock 26 such thattrigger lock 26 is free to pivot to the unlocked position.

It is also noted that in the rearward-most position of screw stop 306,abutment surface 307 which is formed on the base of screw stop 306 (FIG.11A) and comprises a substantially concave surface is positioned toreceive and engage pivot member 79 of firing link 72.

FIGS. 22–22D illustrate surgical stapling device 10 during the firingstroke of firing trigger 20. As trigger 20 is compressed towardsstationary handle 18, pivot member 79 engages abutment surface 307 onscrew stop 306 and firing trigger 20 is pushed distally. As discussedabove, the distal end of firing trigger 22 is connected through couplingmember 86 to the proximal end of pusher link 74. Accordingly, as firingtrigger 20 is moved distally, pusher link 74 is moved distantly toeffect advancement of, pusher back 186 within shell assembly 31. Fingers190 of pusher back 186 engage and eject staples 230 from staple guide192.

Cylindrical knife 188 is moved concurrently with pusher back 186 suchthat knife 188 moves into engagement with cutting ring 128 and backupplate 126. As discussed above, cutting ring 128 is preferably formedfrom polyethylene and backup plate 126 is preferably formed from metal.When knife 188 engages cutting ring 128, it cuts through cutting ring128 and pushes backup plate 126 deeper into anvil head 124 to move tabs150 from engagement with top surface 154 a of center rod 154 (FIG. 16B).Anvil head 124 is now free to pivot about member 164 and is urged to doso by plunger 156 (FIG. 24F). It is noted that because the anvilassembly is in juxtaposed alignment with shell assembly 31, the anvilhead 14 will not pivot fully until the anvil and shell assemblies havebeen unapproximated a distance sufficient to allow the anvil head tofully pivot.

As illustrated in FIG. 22C, projection 93 on firing trigger 20 isaligned with drive member 558 of lockout sleeve 522. When firing trigger20 is fully actuated, projection 93 engages drive member 588 to deflecttab 556 upwardly to disengage retaining surface 556 a from surface 562of inner wall of stationary handle 18. When this occurs, spring 560which is in compression drives lockout sleeve 522 rearwardly withinhandle 18 such that a portion of sleeve 522 engages locking portion 542of trigger lock 26 to pivot trigger lock 26 from the unlocked position(FIG. 22C) to the locked position (FIG. 23). In the locked position thedistal end of trigger lock 26 is positioned between abutments 89 and 91.

During actuation of firing trigger 20, an extension 589 on firing link72 engages tactile indicator 580 and moves tactile indicator 580 from aretracted to an extended position. In the extended position, indicator580 is positioned to engage wing 584 of screw stop 306 duringunapproximation of the anvil and shell assemblies (FIG. 22F).

FIGS. 23–23G illustrate surgical stapling device 10 after firing trigger20 has been released. As illustrated, biasing member 106 has urgedpusher link 74 proximally to its retracted position and trigger lock 26has been moved to the locked position in the manner discussed above bylockout sleeve 522. As shown in FIG. 23D, pusher back 186 has moved, inresponse to movement of pusher link 74, proximally to its retractedposition. Anvil head 124 has begun to pivot but is prevented fromfurther pivoting by shell assembly 31.

FIGS. 24–24H illustrates surgical stapling device 10 after it has beenfired and unapproximated. As illustrated, anvil head 124 has been movedto the pivoted position by plunger 156 (FIGS. 24E and 24F). Screw stop306 has been advanced from its rearward-most position adjacent safetybracket 520 to its forward-most position adjacent the proximal end ofpusher link 74. Retainer slide 506, which is supported on screw stop306, has moved with screw stop 306 to a forward position. As retainerslide 506 moves forwardly, spring 502 returns indicator plate 500 to itsforward-most position and spring 536 returns safety bracket 520 to itsforward-most position. As such, indicator plate 500 once againidentifies the device as being in a fire not ready condition and safetybracket 520 moves to a position preventing movement of trigger lock 520.

Referring to FIGS. 24G and 24H, as screw stop 306 is moved from itsrearward-most position (FIG. 23) to its forward-most position withinstationary handle 18, wing 584 of screw stop 306 engages tactileindicator 580 at the point of unapproximation at which anvil head 124pivots (FIG. 24F). This contact between screw stop 306 and tactileindicator 580 provides a tactile and/or audible indication to a surgeonthat the anvil head 124 has tilted and the device can be removed fromthe patient. It is noted that by providing additional force toapproximation knob 22, wing 584 of screw stop 306 will force tactileindicator 580 to return to its retracted position to allow device 10 tobe fully unapproximated.

FIGS. 25–29 illustrate another preferred embodiment of the presentlydisclosed surgical stapling device shown generally as 610. Briefly,surgical stapling device 610 includes a proximal handle portion 612, anelongated central body portion 614 including a curved elongated outertube 614 a, and a distal head portion 616.

Handle portion 612 includes a stationary handle 618, a firing triggerassembly 620, a rotatable approximation knob 622 and an indicator window624. Stationary handle 618 is preferably formed from thermoplastichandle sections, e.g., polycarbonate, which together define a housingfor the internal components of handle portion 612. These internalcomponents will be discussed in detail below. A pivotably mountedtrigger lock 626 is fastened to handle portion 612 and is manuallypositioned to prevent inadvertent firing of stapling device 610.Indicator window 624 defines an opening or translucent surface 628 whichfacilitates viewing of an internally positioned indicator whichidentifies a multiplicity of operational positions of the staplingdevice.

Head portion 616 includes an anvil assembly 630 and a shell assembly631. Each of these assemblies will be discussed in detail below. Exceptwhere otherwise noted, the components of surgical device 610 are formedfrom thermoplastics including polycarbonates and metals includingstainless steel and aluminum. The particular material selected to form aparticular component will depend upon the strength requirements of theparticular component. For example, the anvil will be formed from ametal, such as stainless steel, and the stationary handle will be formedfrom a thermoplastic such as polycarbonate. Alternately, other materialsnot listed above may be used to form components of stapling device 610provided the materials are suitable for surgical use and meet thestrength requirements of the particular component.

FIG. 30 illustrates handle portion 612 of surgical stapling device 610with a section of stationary handle 618 removed to expose the internalcomponents of handle portion 612. Handle portion 612 houses an indicatormechanism and the proximal components of an approximation mechanism anda firing mechanism. Each of these mechanisms will be described in detailhereinbelow. A cushion non-slip grip 619 is fastened to stationaryhandle 612. Grip 619 may be formed from rubber or neoprene and securedto stationary handle 18 using an overmolding process. Alternately, othermaterials and attachment methods not mentioned here may be used.

Referring to FIGS. 30–36, the approximation mechanism includesapproximation knob 622, a rotatable sleeve 633, a screw 632, first andsecond screw extensions 634 and 636, respectively, and anvil retainer638 (FIG. 34). Rotatable sleeve 633 includes a small diametercylindrical hollow body portion 640 and a large diameter hollow bodyportion 642. Body portion 642 includes an annular groove 644 dimensionedto receive an inwardly extending annular flange 646 formed on aninternal wall of stationary handle 618. Engagement between groove 644and flange 646 axially fixes sleeve 633 within stationary handle 618while permitting relative rotation. The proximal end of body portion 640of rotatable sleeve 633 extends through an opening formed in theproximal end of stationary handle 618 and includes a flat surface 648.Approximation knob 622 includes a bore 649 configured to receive theproximal end of sleeve 633 such that rotation of knob 622 effectsconcurrent rotation of sleeve 633.

Screw 632 is dimensioned to be slidably positioned within rotatablesleeve 633. A helical channel 650 is formed in the proximal end of screw632. A pin 652 extends radially through body portion 642 of sleeve 633into helical channel 650. Since sleeve 633 is axially fixed with respectto stationary handle 618, rotation of sleeve 633 about screw 632 causespin 652 to move along channel 650 of screw 632 to effect axial movementof screw 632 within stationary handle 618.

The distal end of screw 632 includes an extension 654 having upper andlower flat surfaces and a throughbore 656. Top and bottom screwextensions 634 and 636 each include a flexible flat band portion 658 anda distal semi-cylindrical portion 660. The flexibility of top and bottomscrew extensions 634 and 636 facilitate movement of screw extensions 634and 636 through curved elongated body portion 614. The proximal end ofeach band portion 658 includes an opening 662 dimensioned to receive apin 664 for securing the proximal end of screw extensions 634 and 636 toextension 654 of screw 632 via throughbore 656. Each semi-cylindricalportion 660 of screw extensions 634 and 636 includes an outwardlyextending projection 666. When top and bottom screw extensions 634 and636 are positioned in juxtaposed alignment, semi-cylindrical portions660 of screw extensions 634 and 636 together define a cylindrical memberwhich is dimensioned to be received within a proximal end of anvilretainer 638. Projections 666 are dimensioned to be received in openings668 formed in the proximal end of anvil retainer 638 to fasten anvilretainer 638 to the distal end of screw extensions 634 and 636. Thedistal end of anvil retainer 638 includes a plurality of flexible legs670 which are configured to flex outwardly to receive and engage theanvil assembly as will be discussed in further detail below.

In operation, when approximation knob 622 is manually rotated, rotatablesleeve 633 is rotated about the proximal end of screw 632 to move pin652 along channel 650 of screw 632. Since sleeve 630 is axially fixed tostationary handle 618, as pin 652 is moved through channel 650, screw632 is advanced or retracted within stationary handle 618. As a result,top and bottom screw extensions 634 and 636, which are fastened to thedistal end of screw 632, and anvil retainer 638, which is fastened tothe distal end of screw extensions 634 and 636, are moved axially withinelongated body portion 614. Since anvil assembly 630 is secured to thedistal end of anvil retainer 638, rotation of approximation knob 622will effect movement of anvil assembly 630 in relation to shell assembly631 between spaced and approximated positions.

Referring again to FIGS. 30–35, the firing mechanism includes firingtrigger 620, a firing link 672, and an elongated pusher link 674. Firingtrigger 620 includes a pair of trigger plates 676 and 678, a triggercover 680, and a cushioned gripping member 682. See also FIGS. 39 and40. Gripping member 682 is preferably formed from rubber or neoprene andovermolded onto trigger cover 680. Alternately, other cushioned non-slipgripping materials may be used and fastened to trigger cover using anyknown technique, e.g., adhesives. The distal end of each of triggerplates 676 and 678 includes a hinge portion 676 a and 678 a,respectively, having a hole for receiving a pivot member 684. Pivotmember 684 is dimensioned to extend between hinge portions 676 a and 676b through a bore 677 formed in a connector 686 secured to the proximalend of pusher link 674 to pivotably secure the distal end of firingtrigger 620 to the proximal end of pusher link 674. Alternately,connector 686 may be formed integrally with pusher link 674. The topsurface of each trigger plate 676 and 678 includes a notch 683dimensioned to receive a locking pin 693 to prevent inadvertent firingof device 610.

Firing link 672 includes a right-side link portion 672 a and a left-sidelink portion 672 b interconnected by a spacer 672 c (FIG. 31A). Eachlink portion includes a pivot opening 688 at each end thereof and acentrally positioned elongated slot 690. The space between link portions672 a and 672 b is dimensioned to receive a safety link 692. Thefunction and operation of safety link 692 will be described in detailbelow. One end 694 of firing link 672 is pivotably connected betweenopenings 679 (FIG. 40) in trigger plates 676 and 678 about pivot member696. The other end 698 of firing link 672 is pivotably connected tostationary handle 618 about pivot member 700. Pivot member 700 issupported in a vertically oriented pocket 702 (only one is shown) formedalong the internal wall of stationary handle 618. Pivot members 696 and700 may be formed as pins, integral nubs formed on firing link 672, orany other structure which provides the desired function.

Safety link 692 includes a body portion 692 a having a guide member 692b formed at one end thereof and a bore 692 c formed at an opposite endthereof. Bore 692 c is dimensioned to receive a locking pin 693. Safetylink 692 is positioned between right-side link portion 672 a andleft-side link portion 672 b of firing link 672. Locking pin 693 isslidably positioned in slots 690 of firing link 672 and guide member 692b is slidably positioned in a horizontal slot 695 formed along theinternal wall of stationary handle 618. A biasing member, e.g., coilspring 697, is secured between end 694 of firing link 672 and a centralportion of safety link 692 to bias safety link 692 towards end 694 offiring link 672. Body portion 692 a of firing link includes a weakenedportion 699. The purpose of weakened portion 699 will be discussed indetail below.

Elongated pusher link 674 includes a flange 704 positioned about itsproximal end distally of connector 686. A spring 706, positioned betweena forward end of stationary handle 618 and flange 704, biases pusherlink 674 to a retracted, non-fired position. A pair of wings 708 extendradially outwardly from the proximal end of pusher link 674. Wings 708are dimensioned to slide along slots 710 formed along the internal wallsof stationary handle 618 to maintain proper alignment of pusher link 674within stationary handle 618 during firing of device 610. The distal endof pusher link 674 includes a pair of flexible arms 710 which aredimensioned to extend through slots 820 (FIG. 50) formed in the proximalend of pusher back 786. Pusher back 786 forms part of shell assembly 631and will be discussed in greater detail below. Pusher link 674 ispreferably formed from a flexible plastic material and includes aplurality of notches 787 which allow the pusher link to bend more easilyas it moves through body 614. An annular channel 674 a is formed aboutpusher link 674 to receive an o-ring seal 674 b. Operation of the firingmechanism of the device will be described in detail below.

As discussed above, head portion 616 includes anvil assembly 630 andshell assembly 631. Referring to FIGS. 41–46, anvil assembly 630includes an anvil head assembly 720 and an anvil center rod assembly752. Anvil head assembly 720 includes a post 722, an anvil head 724, abackup plate 726, a cutting ring 728 and an anvil 729. Anvil head 724includes a central hole 732 dimensioned to receive post 722, an innerannular ring 734, and an outer annular ring 736. Anvil 729 is supportedon anvil head 724 in an annular channel 738 defined between annularrings 734 and 736. Anvil 729 includes a plurality of pockets 740 forreceiving and deforming staples. A tab 742 formed on anvil 729 isdimensioned to be received in a slot 744 formed in anvil head 724 tomaintain proper alignment of anvil 729 and anvil head 724. Cutting ring724 and backup plate 726 each include a central opening and arepositioned about post 722 in stacked relation in an annular channel 746defined between central hole 732 and annular ring 734. Preferably,cutting ring 724 is formed from polyethylene and is fixedly secured tobackup plate 726 using, for example, adhesives. Cutting ring 724includes a pair of diametrically opposed slots 748 dimensioned toreceive tabs 750 formed on backup plate 726. The cutting ring 726 andbackup plate 748 assembly is slidably mounted about post 722.

Anvil center rod assembly 752 includes anvil center rod 754, a plunger756 and plunger spring 758. A first end of center rod 754 includes atransverse throughbore 760 (FIG. 44) which is spaced radially of acentral longitudinal axis of center rod 754. Post 722 of anvil headassembly 720 also includes a transverse throughbore 762. A pivot member764 pivotably secures post 722 to center rod 754 such that anvil headassembly 720 is pivotably mounted to anvil center rod assembly 752. Asbest seen in FIGS. 45 and 46, plunger 756 is slidably positioned in abore 766 formed in the first end of center rod 754. Plunger 756 includesan engagement finger 768 which is offset from the pivot axis of anvilhead assembly 720 and biased into engagement with the base of post 722by plunger spring 758 to urge anvil head assembly 720 to a pivotedposition. In a prefired position, tabs 750 formed on backup plate 726engage a top surface 754 a of center rod 754 to prevent anvil headassembly 720 from pivoting (see FIGS. 63 and 64). As device 610 is beingfired, backup plate 726 and cutting ring 728 are moved deeper into anvilhead 724 about post 722 by knife 788 to move tabs 750 out of engagementwith top surface 754 a of center rod 754 to permit plunger 756 to pivotanvil head assembly 720 about pivot member 764. See FIGS. 66–68. Asillustrated in FIG. 68, the upper end of 754 b of center rod 754 isangled to further accommodate a tissue specimen. It is noted that afterthe device has been fired, the anvil will only move to the tiltedposition after the anvil assembly and the shell assembly have beenunapproximated a predetermined distance.

A second end of center rod 754 includes a blind bore 770 (FIGS. 45 and46). Blind bore 770 includes an inwardly tapering opening 772 and aspaced annular recess 774. Blind bore 770 is dimensioned to receive aremovable trocar 776. Annular recess 774 is positioned within blind bore770 and dimensioned to receive annular rib 778 formed on trocar 776 tosecure center rod 754 in engagement with trocar 776. The outer surfaceof center rod 754 also includes an annular abutment 775. Annularabutment 775 is dimensioned to be received within an annular recess 777(FIG. 50) formed in the distal end of anvil retainer 638 to retain anvilassembly 630 within anvil retainer 638.

Referring to FIGS. 34 and 50, shell assembly 631 includes a shell 782, asleeve 784, a pusher back 786, a cylindrical knife 788, a pusher 790 anda staple guide 792. Shell 782 includes an outer housing portion 794 andan inner guide portion 796. Sleeve 784 is fixedly positioned withininner guide portion 796 of shell 782 and defines a stepped bore 785. Alocking member 787 having a detent 789 (FIG. 34A) is retained within thestepped bore 785. Outer housing portion 794 defines a throughbore 798having a distal cylindrical section 800, a central conical section 802and a proximal smaller diameter cylindrical section 804. A plurality ofopenings 806 are formed in conical section 802. Openings 806 aredimensioned to permit fluid and tissue passage during operation of thedevice. A pair of diametrically opposed flexible engagement members 807are formed on proximal cylindrical section 804 of shell 782. Engagementmembers 807 are positioned to be received in openings 809 formed on thedistal end of elongated body 614 to secure shell 782 to elongated body614. A pair of openings 811 are formed in the proximal end of outer tube614 a. Openings 811 are dimensioned to receive protrusions (not shown)formed on the internal wall of stationary handle 618 to facilitateattachment of tube 614 a to handle portion 612.

Pusher back 786 includes a central throughbore 808 which is slidablypositioned about inner guide portion 796 of shell 782. Pusher back 786includes a distal cylindrical section 810 which is slidably positionedwithin distal cylindrical section 800 of shell 782, a central conicalsection 812 and a proximal smaller diameter cylindrical section 814. Adistal face of pusher back 786 includes an inner annular shoulder 816and an outer annular recess 818. The proximal end of pusher back 786includes a pair of slots 820 configured to receive flexible arms 710 ofpusher link 674 to fasten pusher link 674 to pusher back 786 such that adistal face of pusher link 674 abuts a proximal face of pusher back 786(see FIG. 53).

Pusher 790 includes a body 822 having a proximally extending ring 824and a multiplicity of distally extending fingers 826 dimensioned to beslidably received within slots 828 formed in staple guide 792 to ejectstaples 830 therefrom. Ring 824 is dimensioned to be received withinannular recess 818 formed in the distal face of pusher back 786 tofasten pusher 790 to pusher back 786. Cylindrical knife 788 includes aplurality of radially extending tabs 832 formed about its proximal endand is positioned within annular shoulder 816 of backing 786 with tabs832 positioned between the distal face of pusher back 786 and body 822of pusher 790 to fixedly secure knife 788 in relation to pusher 790. Thedistal end of knife 788 includes a circular cutting edge 834.

In operation, when pusher link 674 is advanced distally in response toactuation of firing trigger 620, as will be described below, pusher back786 is advanced distally within shell 782. Advancement of pusher back786 effects advancement of pusher 790 and knife 788. As pusher 790 isadvanced, fingers 826 engage staples 830 positioned within slots 828 instaple guide 792 to eject staples 830 from staple guide 192.

Referring to FIGS. 34, 36, 51 and 52, stapling device 610 includes aretractable trocar assembly slidably positioned within anvil retainer638. The retractable trocar assembly includes a trocar 840 and aengagement member 842. Engagement member 842 may be in the form of aspring clip, as shown. Alternately, other engagement members areenvisioned, e.g., spring loaded protrusions, etc. Trocar 840 includes aslot 844 which extends through the body of trocar 840 along a portion ofits length. Slot 844 is dimensioned to receive engagement member 842.Engagement member 842 includes a proximal body portion 846 and a pair ofdistally extending resilient legs 848. Each leg 848 includes a taperedtip 850 and a proximally facing shoulder 852. A pin 854 is positionedthrough openings 856 and 858 formed in body portion 846 of member 842and trocar 840, respectively, to secure engagement member 842 withinslot 844 of trocar 840. Pin 854 also extends through an elongated slot855 formed in anvil retainer 638, such that the distal and proximalsurfaces of slot 855 function as stops to define the fully advanced andfully retracted positions of the retractable anvil assembly. Legs 848are formed of a resilient material such as spring steel. In an unbiasedposition, legs 848 of member 842 extend outwardly of trocar 840 andanvil retainer 638 such that in the fully advanced position of trocar840, shoulders 852 of legs 848 engage a distal end of anvil retainer 638to retain the trocar 840 in the advanced position. See FIG. 51.

Referring to FIG. 53, when the anvil assembly 630 is attached to anvilretainer 638, anvil center rod 754 of anvil assembly 630 is slid overtapered tips 852 of legs 848 to compress legs 848 inwardly in thedirection indicated by arrow “A” such that trocar 840 and member 842move inside blind bore 770 of center rod 754. When the tip of trocar 840engages the bottom of bore 770, further movement of center rod 754towards anvil retainer 638 in the direction indicated by arrow “B”causes the trocar assembly to move to the retracted position withinanvil retainer 638.

Referring to FIG. 53A, when the anvil assembly is disengaged from anvilretainer 638 by pulling the anvil assembly in the direction indicated byarrow “C”, legs 848 flex outwardly to move shoulders 852 of legs 848 ofmember 842 into annular recess 774 of center rod 754. As a result, asanvil assembly 630 is disengaged from anvil retainer 638, member 842 andthus trocar 840 are pulled distally in the direction indicated by arrow“D” with the anvil assembly to the advanced position as shown in FIG.57.

The proximal end of trocar 840 includes a blind bore 841. A rigidflexible wire 843 has a distal end which is secured within bore 841 oftrocar 840 and extends rearwardly through elongated body portion 614 andinto handle portion 612 of stapling device 610. Wire 843 has a proximalend which is secured to an indicator assembly in handle portion 612which will be discussed in detail below.

Referring again to FIGS. 34, 36, 51 and 52, a cylindrical lockout tube870 is slidably positioned about the outer surface of anvil retainer 638and positioned to extend through inner guide portion 796 of shell 782,sleeve 784 and locking member 787 of shell assembly 631. The proximalend of lockout tube 870 includes an annular protrusion 872 (FIG. 34B).Locking member 787, which is fixedly positioned within sleeve 784 ofshell assembly 631, includes a detent 789 (FIG. 34A) dimensioned tofrictionally receive annular protrusion 872 to prevent sliding movementof lockout tube 870 about anvil retainer 638 until a predetermined forcehas been exerted on lockout tube 870. Lockout tube 870 is positionedabout flexible legs 670 of anvil retainer 638 to provide rigidity tolegs 670 during approximation of the anvil to prevent anvil assembly 630from becoming inadvertently detached from anvil retainer 638. Movementof cylindrical lockout tube 870 about anvil retainer will be discussedin more detail below.

Referring to FIGS. 33, 35, 37, 38A, and 69–72 an indicator assembly ismounted within stationary handle 618 and includes an indicator 900 withindicia 901 a, 901 b and 901 c which provides a visual indication to asurgeon via indicator window 624 that the anvil assembly is not attached(901 a), that the anvil assembly is attached (901 b), or that anvilassembly is attached and approximated 901 c, i.e., the device is readyto fire. The indicia 901 a–c may include red, yellow, and greencoloring, respectively. Alternately, other color coded, graphic, orwritten indicia may be used to indicate the above described deviceconditions.

The indicator assembly includes an indicator 900, an indicator subplate902, an indicator arm 904, a screw stop 906 and a rotatable disk 908.Screw stop 906 includes a throughbore 910 dimensioned to be positionedabout screw 632. A set screw 912 is used to fixedly secure screw stop906 to screw 632. Disk 908 includes a central throughbore 914, anupwardly extending cam member 916 and a wire connector 918. Disk 908 isrotatably secured to the top of screw stop 906 by screw 920. Wireconnector 918 includes a post 922 which extends through an opening 924in disk 908 and is rotatably fixed therein by a D-clip 926 or the like.Wire connector 918 includes a bore 928 for receiving one end of wire843. A pin 930 secures wire 843 to wire connector 918, such that whenwire 843 is advanced or retracted in response to attachment ordetachment of anvil assembly 630 onto or from anvil retainer 638, asdiscussed above, disk 908 will rotate about screw 920 to rotate cammember 916.

Indicator subplate 902 is fixedly secured between internal walls ofstationary handle 618 via a notch 934 formed in subplate 902 andchannels (not shown) formed in the internal walls of stationary handle618. A centrally disposed cutout 932 defining on elongated channel 936is formed in subplate 902. Indicator arm 904 also includes a cutout 937having a first end 937 a and a second end 937 b. A projection 938 whichis slidably and rotatably positioned in elongated channel 936 extendsdownward from indicator arm 900 in subplate 902. A projection 940extends from a top surface of indicator arm 904 into a curved bore 941formed in the bottom of indicator 900. A projection 943 extendsdownwardly from indicator 900 and is positioned in channel 936 ofsubplate 902 to rotatably secure indicator 900 to subplate 902. Thebottom of indicator 900 also includes a cam slot 942 for receiving cammember 916 of disk 908.

In the assembled condition, indicator subplate 902 is fixedly securedwithin stationary handle 618, with indicator arm 904 and indicator 900slidably and rotatably mounted thereon and curved bore 941 of indicator900 positioned on projection 940 of indicator arm 904. The entireassembly is engaged and maintained in an assembled state by indicatorwindow 624. Cam member 916 extends upwardly from disk 908 throughchannel 936 in subplate 902 and cutout 937 in indicator arm 904 into camslot 942 formed in the bottom of indicator 900. A spring 952 supportedbetween indicator subplate 902 and indicator arm 904 biases indicatorarm 904 towards the end of subplate 902 supporting indicator 900.Referring also to FIGS. 73–75, prior to attaching anvil assembly 630 toanvil retainer 638, indicia 901 a (e.g., red dot) is positioned beneathopening 628 of indicator window 624 (FIG. 73). When anvil assembly 630is attached to anvil retainer 638 in the manner described above, trocar840 is retracted, i.e., pushed proximally, within anvil retainer 638 tomove wire 843 proximally. Wire 843 is secured to connector 918 which issecured to the bottom of disk 908. As wire 843 is moved proximally, disk908 is rotated in the direction indicated by arrow “E” on screw stop 906about screw 920 to move cam member 916 which is positioned within thecam slot 942 formed in the bottom of indicator 900 in the samedirection. Movement of cam member 916 against cam slot 942 causesindicator 900 to rotate in the direction indicated by arrow “F” aboutprotrusion 943 to move indicia 901 b (e.g., yellow dot) beneath opening628 of indicator window 624 (FIG. 25). Cam member 916 also engagescutout 937 of indicator arm 904 near first end 937 a of cutout 937 torotate arm 904 in the direction indicated by arrow “G” about protrusion938 to the position shown in FIG. 74. As discussed above, indicia 901 bindicates to a surgeon that the anvil has been attached to the anvilretainer.

Next, when the surgeon approximates the device, screw 632 is movedproximally in the manner described above. Thus, screw stop 906, which ismounted on screw 632, and disk 908, including cam member 916, are movedproximally. As cam member 916 is moved proximally, cam member 916 movesout of cam slot 942 in indicator 900 and moves from first end 937 a ofcutout 937 formed in indicator arm 904 to second end 937 b of cutout937. When cam member 916 reaches second end 937 b of cutout 937, cammember 916 engages a wall 950 of indicator arm 904 and drags indicatorarm 904 proximally, against the bias of spring 952. As indicator arm 904is moved proximally in the direction indicated by arrow “H”, indicator900 is also moved proximally to move indicia 901 c (e.g., green light)beneath opening 628 of indicator window 624. As discussed above, indicia901 c indicates to a surgeon that the anvil assembly has been attachedto the anvil retainer 638 and approximated, i.e., the instrument isready to fire.

Operation of surgical stapling device 610 will now be described indetail.

FIGS. 47–51 illustrate surgical stapling device 610 with anvil assembly631 attached to anvil retainer 638 in the unapproximated position. Asshown in FIGS. 47 and 49, screw 632 is in its distal-most position, withscrew stop 906 positioned adjacent the proximal end of pusher link 674.In this position, locking pin 693, which is secured to safety link 692(FIG. 31) is positioned in notches 683 on firing trigger plates 676 and678 (FIG. 39) to prevent actuation of firing trigger 620. As shown inFIG. 50, legs 670 of anvil retainer 638 are positioned about center rod754 of anvil assembly 630 such that abutment 775 of center rod 754 ispositioned within annular recess 777 of anvil retainer 638. Annularprotrusion 872 of lockout tube 870 is positioned within detent 789 oflocking member 787 (FIG. 54A) to fix lockout tube 870 about legs 670 ofanvil retainer 638 during approximation of the device. As anvil retainer638 is retracted into lockout tube 870 during approximation, the exposedlength of legs 870 of anvil retainer 638 will shorten to increase theforce required to remove anvil assembly 630 from anvil retainer 638.When anvil retainer is retracted into lockout tube 870 a predetermineddistance, shoulder 871 on anvil retainer 638 will engage the distal endof lockout tube 870 (FIG. 54B) to force annular protrusion 872 fromdetent 789 and force lockout tube 870 proximally with anvil retainer638.

Referring to FIGS. 56 and 57, anvil assembly 630 and shell assembly 631are approximated by rotating approximation knob 622 in the directionindicated by arrow “J” in FIG. 56. Rotation of knob 622 effects rotationof sleeve 633 to move sleeve pin 652 along channel 650 of screw 632.Since sleeve 633 is axially fixed to stationary handle 618, as pin 652is moved through channel 650, screw 650 is moved proximally withinstationary handle 618. As screw 650 is moved proximally, it pulls screwextensions 634 and 636, anvil retainer 638 and anvil assembly 630proximally. Anvil assembly 630 is approximated into juxtaposed alignmentwith shell assembly 631.

As illustrated in FIG. 56, as screw 632 is moved proximally withinstationary handle 618, screw stop 906, which is fixedly secured to screw632, also moves proximally. Screw top 906 includes a downwardlyextending abutment 1000 and a concavity 1002. During the final stages ofapproximation, abutment 1000 engages guide member 692 b of safety link692 and pulls safety link 692 proximally such that guide member 692 bmoves along slot 695 in internal wall of stationary handle 618 againstthe bias of spring 697. As safety link 692 is moved proximally, lockingpin 693 moves upwardly in channel 690 of firing link 672 and locking pin693 is moved out of engagement with notches 683 in firing trigger 620 toactivate the firing trigger.

As illustrated in FIG. 57A, shoulder 871 on anvil retainer 638 has movedlockout tube 870 proximally such that annular protrusion 872 on lockouttube 870 is no longer positioned in detent 789 of locking member 787.

FIGS. 58–61 illustrate handle portion 62 of surgical stapler 610 duringthe firing stroke of trigger 620. After anvil 630 and shell assembly 631have been approximated, pivot member 700 on end 698 of firing link 672is positioned in concavity 1002 of screw stop 906 and locking pin 693 ispositioned proximally of notches 683. Trigger lock 626 has also beenreleased, i.e., manually pivoted to an unlocked position. Surgicalstapling device 610 is now in a firing position.

To fire stapling device 610, firing trigger 620 is pivoted in thedirection indicated by arrow “K”. Since pivot member 700 is locked inconcavity 1002 of screw stop 906, trigger 620 is forced to movedistally. Trigger 620 is secured to the proximal end of pusher link 674by pivot member 684. Thus, pusher link 674 is also moved distally withinelongated body portion 614. Concurrently, a top surface of triggerplates 676 and 678 engages locking pin 693 to force guide member 692 bof safety link 692 further proximally in the direction indicated byarrow “L” along slot 695. When firing trigger 620 reaches the end of itsfiring stroke, an engagement member 1010 formed on firing trigger 620engages weakened portion 699 of safety link 692 (FIG. 60) to breaksafety link 692 into two parts (FIG. 61). As safety link 692 breaks, anaudible and tactile indication is given to the surgeon that firing iscomplete. When firing trigger 620 is released (FIG. 61), spring 706returns pusher link 674 to the retracted position. Spring 697 alsoreturns locking pin 693 into engagement with notches 683 in firingtrigger 620 to prevent further pivoting of firing trigger 620. Sincesafety link 692 is broken, approximation of device 610 will not removelocking member 693 from notches 683.

FIGS. 62 and 65 illustrate head portion 616 of surgical stapling device610 immediately prior to and immediately after the firing stroke offiring trigger 620. As discussed above, as pusher link 674 is moved inthe direction indicated by arrow “M” in FIG. 65, pusher back 786 andpusher 790 are advanced distally such that fingers 826 are pushedthrough slots 828 to force staples 830 through tissue 1040 into pockets740 of anvil 729. Simultaneously, circular knife 788 is advanced to corethe tissue. As knife 788 is advanced distally, knife 788 engages andmoves cutting ring 728 and backup plate 726 further into anvil head 724to move tabs 750 of backup plate 726 out of engagement with center rod754. See FIGS. 66–68. By moving tabs 750 out of engagement with centerrod 754, as discussed above, anvil head assembly 720 is free to pivotabout pivot member 764 on center rod 754 after anvil assembly 630 andshell assembly 631 have been unapproximated.

Surgical stapling device 610 is used to perform a circular anastomoses.Typically, circular anastomoses are required during procedures forremoving a portion of a diseased vessel such as the colon or theintestine. During such a procedure, the diseased portion of the vesselis removed and the remaining vessel section end portions are joinedtogether using a surgical stapling device.

During such a procedure using surgical stapling device 610, prior toremoving the diseased vessel portion, anvil assembly 630 with removabletrocar 776 attached thereto (FIG. 46) is positioned in a first vesselsection on a first side of the diseased vessel portion. Removable trocar776 includes bore 776 a for receiving a suture line for manipulating theanvil assembly. After the diseased vessel portion is removed and theopen ends of the first and second vessel sections have been sutured, thedistal end of device 610 as shown in FIG. 51 is positioned in the secondvessel section on the other side of the diseased (now removed) vesselportion. At this time, trocar 776 is pushed through the suture line inthe end of the first vessel section and removed from center rod 754.Next, trocar 840 is pushed through the suture line in the second vesselsection. Center rod 754 is now positioned about trocar 840 and pushedinto anvil retainer 638 to secure anvil assembly 630 to anvil retainer638 (FIG. 52). Surgical stapling device 610 can now be approximated andfired in the manner discussed above, to join the ends of the first andsecond vessel sections and core out any tissue obstructing the vesselsection lumen. After surgical stapling device is fired andunapproximated, head assembly 720 will tilt to the position shown inFIG. 68 to reduce the profile of the anvil assembly and simplify removalof the instrument from the vessel lumen. It has been contemplatedproviding an engagement member in handle portion 612 which would engagea component of the approximation mechanism during unapproximation of theanvil assembly to provide a tactile and/or audible indication that theanvil head assembly has been unapproximated a sufficient distance totilt. It is envisioned that the engagement member may be moved to aposition aligned with a component of the approximation mechanism by thefiring trigger.

It will be understood that various modifications may be made to theembodiments disclosed herein. For example, the materials used toconstruct the individual components of the device may be chosen from avariety of known materials to achieve the desired result. Moreover, theparticular indicia formed on the indicator may be other than thatdisclosed herein, i.e., other indicia is envisioned. Therefore, theabove description should not be construed as limiting, but merely asexemplifications of preferred embodiments. Those skilled in the art willenvision other modifications within the scope and spirit of the claimsappended hereto.

1. A surgical stapling device comprising: an elongated pusher linkincluding a body defining a longitudinal axis and having a proximal end,a distal end, annular portions adjacent its respective proximal anddistal ends, and an elongated curved intermediate portion between and incommunication with the annular portions; a firing actuator locatedproximally of and coupled to the proximal end of the pusher link; ashell assembly operatively associated with the distal end of the pusherlink, the shell assembly housing a plurality of staples and having andelongated member that is connectable to an anvil assembly; an elongatedtubular shaft having an elongated bore for housing the pusher link, anda pair of elongated substantially flat extension members housed in andalong a diameter of the tubular shaft; wherein at least a portion of thecurved intermediate portion of the pusher link has a substantiallyU-shaped configuration when viewed in vertical section taken transverseto the longitudinal axis of the pusher link, the U-Shaped configurationincluding a bottom wall disposed to one side of the diameter of thetubular shaft, each end of the bottom wall having an adjoiningupstanding side wall that extends transversely through the diameter andalong a portion of the interior surface of the bore of the tubularshaft, the bottom wall having a thickness that is less than half of theradius of the bore of the tubular shaft.